There is an extensive body of research on the factors that are associated with reproductive health, focusing on factors within the adolescent as well as within the various components of the adolescents environment. This paper presents a selective review of the research pertaining to each layer of the adolescent's ecosystem. Emphasized are (1) studies that are rigorously implemented, experimental evaluations of interventions, in which aspects of the environment are manipulated and reproductive health outcomes are examined; and (2) studies that are multivariate, involving the examination of aspects of the environment as predictors of reproductive health outcomes taking background characteristics into account. Throughout this paper, the aim is to go beyond the broad identification of which factors appear to be linked to adolescent reproductive health, to the identification of specific strategies that have been attempted and evaluated, and/or for which there is evidence that initiating programs with these activities has the potential to contribute to improved adolescent reproductive health outcomes. These studies indicate that interventions addressing the antecedents of adolescent pregnancy and STIs can be effective, with early childhood, youth development, community volunteer learning programs, and nurse home visiting approaches appearing as important complements to traditional sexuality and HIV education programs and clinic service approaches. (Contains 167 references and a research summary table.) (GCP)